Wideband Voltage Amplifier HVA


  • Bandwidth DC to 10, 200 or 500 MHz
  • Fixed or variable gain up to 60 dB (x 1,000)
  • Noise down to 0.9 nV/√Hz
  • True DC coupling, switchable to AC
  • 50 Ω bipolar or 1 MΩ FET input stage 
Lower Cut-Off FrequencyDC/1 kHzDC/1 HzDC/1 kHzDC/1 HzDC
Upper Cut-Off Frequency10 MHz10 MHz200 MHz200 MHz500 MHz
Input Impedance50 Ω1 MΩ50 Ω1 MΩ50 Ω
Gain [dB]40/6040/6020/4020/4020
Eingangsspannungsrauschen [/√Hz]0.9 nV4.7 nV1.2 nV4.5 nV3.0 nV
Input Voltage Drift1 µV/°C2 µV/°C1 µV/°C5 µV/°C10 µV/°C
Datasheet DownloadDownloadDownload Download Download

Output impedance 50 Ω. Offset adjustable by trimpot. Output short-circuit protected. Power supply via 3-pin Lemo® socket. A mating connector is provided with the device. Optional power supply PS-15 available. For further information please view the datasheet or contact FEMTO.


For optimum signal-to-noise performance choose an amplifier with sufficient bandwidth corresponding to the required signal bandwidth. However, keep in mind that unnecessary high bandwidth introduces more wideband noise. Therefore, FEMTO offers HVA Voltage Amplifiers with three different upper cut-off frequencies to match individual measurement requirements. And as with all FEMTO Adjustable-Gain Amplifiers the bandwidth remains constant when switching between the different gain settings which is very important for measuring fast signals and pulses.

True DC-coupling with zero output offset

True DC-Coupling is extremely important for accurate pulse amplification and analysis especially when different pulse lengths occur like in digital codes or transients with micro- to millisecond duration. If the amplifier is AC coupled or has a large output offset to be de-coupled by the AC setting of the oscilloscope there will be significant undershoots and baseline shifts in the measurements. Therefore, all HVA Amplifiers offer a true DC coupling and an adjustable output offset control even with the 500 MHz model.

Very low input noise

Low input noise is very important for a good signal-to-noise ratio, especially when amplifying small signals. All HVA Amplifiers are optimized for minimum input noise reaching excellent values as low as 0.9 nV/√Hz.


  • Oscilloscope and transient recorder preamplifier
  • Photomultiplier and microchannel-plate amplifier
  • Time-resolved pulse and transient measurements
  • Amplification of digital signals (no baseline shift at any digital code)

Related products / accessories

Power Supply